On the Influence of Composition and Structure of Carbon-Supported Pt-SnO2 Hetero-Clusters onto Their Electrocatalytic Activity and Durability in PEMFC

Presnyakova Presnyakova,Pushkareva Pushkareva,Pushkarev Pushkarev,Presnyakov Presnyakov,Spasov Spasov,Grigoriev Grigoriev,Ivanova Ivanova,Fateev Fateev,Chumakov Chumakov

doi:10.3390/catal9100803

Abstract

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current–voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected.

Highlights

Polymer electrolyte membrane fuel cells (PEMFCs) are becoming a feasible candidate for applications in portable and automotive industries
The obtained values of the Pt content correspond to the preliminary calculated before the synthesis
It was shown that formation of Pt-SnO2 clusters has a significant impact on electrochemical performances, structure, and morphology of catalysts

Summary

Introduction

Polymer electrolyte membrane fuel cells (PEMFCs) are becoming a feasible candidate for applications in portable and automotive industries (especially in robotics and unmanned aerial vehicles [1]). Fuel cell performance is significantly determined by commonly used carbon-supported. The dissolution of platinum, the particles enlargement, and the carbon support corrosion are the main reasons causing a loss of activity and a decrease of the catalyst electrochemically active surface area (EASA) [3,4]. The main disadvantage of the carbon carrier is its oxidation under the fuel cell operating conditions and in start/stop modes. The larger the Pt loading and the specific surface area of the Pt nanoparticles, the faster the degradation of the carbon support occurs [5,6,7]. Degradation of the support induces the using of high Pt loading (0.4–5.0 mg cm−2 ) to maintain high operational lifetime and high efficiency

Methods

Results

Conclusion